说明：  这是一个综合的实验程序，实现了对步进电机的控制，包括启动/停止，正转/反转，加速/减速，同时将转速以及正反转信息通过LED显示出来。
(This is a comprehensive experimental procedures, the realization of a stepper motor control, including start/stop, is to switch/reverse, speed up/slow down speed at the same time, as well as positive information displayed through the LED.)